Weather Forecast
The ridge of high pressure should hold steady until tuesday bringing clear skies for one more day. On Wednesday, expect increased cloud throughout the day. Light snowfall amounts are possible on Thursday. Freezing levels should rise gradually to 1500m by the end of the forecast period. Winds will be light and southerly switching to northwesterly by Thursday.
Avalanche Summary
Over the weekend activity was mostly on solar aspects at higher elevations to size 2.5. One exception to that was on Saturday when a size 3 skier-triggered slab avalanche (see incident report database) near Kaslo failed to ground on depth hoar. It was on a northwest aspect at 2500m. This avalanche represents a very low probability/high consequence scenario that seems to be more prevalent at the southeast end of the region. I expect a continued decrease in avalanche activity with the current cooling trend.
Snowpack Summary
January was a snowy month in the South Columbia region and average snowpack depths at 1700m are now between 2 and 3m. The storm snow is well settled on shaded aspects and riders have gained increased confidence on steeper terrain. The surface hoar layer that formed in mid-December is now dormant. At the bottom of the snowpack, there has been talk of basal facets in the south east end of the region, but avalanche activity has been very isolated. Over the weekend there was s spike in alpine temperatures that sparked a significant avalanche cycle. With the more recent cooling pattern there has been a crust recovery on previously sun-exposed slopes, and there has been a general strengthening of the snowpack. If you're heading into the mountains, it's a good time to take stock of evolving layers (crusts, surface hoar) that may be an issue when it finally snows again.
Problems
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.